1. Field of the Invention
The present invention relates to an air filtration unit and, more particularly, to a low-profile, ceiling mountable module or unit specially and economically constructed to provide a uniform, low-velocity, downward flow of filtered air.
2. Description of the Related Art
In the construction of clean rooms used for the manufacture of electronic components, medical devices, and the like, it is usually necessary to provide a supply of filtered air. The air must not only be clean, but should be provided in a low velocity, downward, generally laminar flow so as not to create turbulent zones within the room and to carry contaminants from the room.
Air filtration units are known in the prior art in which the unit is constructed to be supported within one of the grid openings of a ceiling grid. Such units typically include a housing defining a plenum, an upper air inlet, a blower, and a filter medium at the lower opening of the plenum. Low-profile units have been provided in which the blower is mounted within the plenum.
Whatever the construction of the air filtration unit, it is necessary to reduce any turbulence created by the blower, and to arrange the plenum such that a uniform flow of air through the filter medium is attained. In the past, air filtration units have been constructed with baffle plates or internal passageways intended to direct and distribute the flow of air from the blower to the filter. Such measures have tended to make the filtration units more complicated and expensive. Furthermore, the addition of such internal structures makes it more difficult to minimize the height of the unit.
Accordingly there is an unmet need for a clean room air filtration unit having a minimal height or profile and that is simply and economically constructed.